The Effect Of High Dose External Beam Radiation On The EPTFE Prosthesis-arterial Anastomosis

Objective To explore the effect of the high dose external beam radiation on the ePTFE prosthesis-arterial anastomosis.Methods 20 dog's subrenal abdominal aorta were replaced by ePTFE prosthesis graft, and all the animals were randomly divided into 2 groups including the irradiated groups and the control groups which associated or not post-operative external radiation(35Gy) on the anastomosis. All the animals were sacrificed at 4 weeks and 8 weeks after operation for histological and immunohistochemical examination of the prosthesis-arterial anastomosis.Results Marked histological changes caused by external irradiation at 35 Gy were showed at the prosthesis-arterial anastomosis, however, no disunion, rupture and aneurysm was found at the anastomosis. Statistics analysis revealed reduced intima thickness of irradiated groups 6 weeks after irradiation. The different thickness of intima between proximal and distal anastomosis was also existed. The result of immunohistochemical examination keep accordance with the results of the histomorphology and the statistics.Conclusions High dose of external beam(35 Gy) result in marked histological changes at the anastomosis and the irradiation-induced histological changes include fibrosis and necrosis at the anastomosis, fibrosis of the media and necrosis of the adventitia. No disunion, rupture and aneurysm was found at the anastomosis in out study. The irradiation do not increase the risk of thrombosis at the prosthesis graft. The beam showed inhibition of the intima hyperplasia 6 weeks after irradiation, however, the long-term effect of the irradiation on the anastomosis awaits further investigation.